Chemistry Central Journal

http://link.springer.com/journal/13065

List of Papers (Total 1,192)

Modification and comparison of three Gracilaria spp. agarose with methylation for promotion of its gelling properties

In order to improve the gelling properties of agarose, we modified it by methylation. The agarose was prepared from Gracilaria asiatica, G. bailinae, and G. lemaneiformis with alkaline, treated with diatomaceous earth and activated carbon, and anhydrous alcohol precipitation. The methylation reaction process of agarose was performed with dimethyl sulfate while the chemical...

Steam distillation/drop-by-drop extraction with gas chromatography–mass spectrometry for fast determination of volatile components in jujube (Ziziphus jujuba Mill.) extract

BackgroundJujube extract is commonly used as a food additive and flavoring. The unique jujube aroma and the mild sweet aroma of the extract are critical factors that determine product quality and affect consumer acceptability. The aroma changes with changes in the extraction condition, which is typically dependent on the characteristics of volatile oils in the extract. Despite...

Synthesis and anticancer activity of novel quinazolinone-based rhodanines

BackgroundRhodanines and quinazolinones have been reported to possess various pharmacological activities.ResultsA novel series of twenty quinazolinone-based rhodanines were synthesized via Knoevenagel condensation between 4-[3-(substitutedphenyl)-3,4-dihydro-4-oxoquinazolin-2-yl)methoxy]substituted-benzaldehydes and rhodanine. Elemental and spectral analysis were used to confirm...

MOF the beaten track: unusual structures and uncommon applications of metal–organic frameworks

Over the past few decades, metal–organic frameworks (MOFs) have proved themselves as strong contenders in the world of porous materials, standing alongside established classes of compounds such as zeolites and activated carbons. Following extensive investigation into the porosity of these materials and their gas uptake properties, the MOF community are now branching away from...

Isolation, purification, structural analysis and coagulatory activity of water-soluble polysaccharides from Ligustrum lucidum Ait flowers

In this study, Ligustrum lucidum flowers as raw material, the extraction, isolation and coagulatory activity of polysaccharides were carried out for the first time. The crude polysaccharide was obtained by hot water extraction and ethanol precipitation, and preliminarily purified by Sevage method and D101 macroporous resin. Then the polysaccharide was further purified by DEAE-52...

Simultaneous determination of cetirizine, phenyl propanolamine and nimesulide using third derivative spectrophotometry and high performance liquid chromatography in pharmaceutical preparations

BackgroundThe combination between cetirizine (CET), phenylpropanolamine (PPA) and nimesulide (NMS) under trade name Nemeriv Cp tablet is prescribed for nasal congestion, cold, sneezing, and allergy. Among all published methods for the three drugs; there is no reported method concerning estimation of CTZ, PPA and NMS simultaneously and this motivates us to develop new and simple...

Optimization of phenolics and flavonoids extraction conditions of Curcuma Zedoaria leaves using response surface methodology

This study focused on maximizing the extraction yield of total phenolics and flavonoids from Curcuma Zedoaria leaves as a function of time (80–120 min), temperature (60–80 °C) and ethanol concentration (70–90 v/v%). The data were subjected to response surface methodology (RSM) and the results showed that the polynomial equations for all models were significant, did not show lack...

Acidic and enzymatic saccharification of waste agricultural biomass for biotechnological production of xylitol

Background The plant biomass and agro-industrial wastes show great potential for their use as attractive low cost substrates in biotechnological processes. Wheat straw and corn cob as hemicellulosic substrates were acid hydrolyzed and enzymatically saccharified for high xylose production. The hydrolysate was concentrated and fermented by using Saccharomyces cerevisiae and...

A review of phytochemistry, metabolite changes, and medicinal uses of the common sunflower seed and sprouts (Helianthus annuus L.)

The sunflower (Helianthus annuus L.) seed and sprout is a ubiquitous crop with abundant nutrients and biological activities. This review summarizes the nutritional and medical importance currently recognized but under-researched concerning both seed and sprout highlighting the potential benefits of their phytochemical constituents including phenolic acids, flavonoids and...

Synthesis and biological evaluation of tricyclic matrinic derivatives as a class of novel anti-HCV agents

Background 12N-benzyl matrinic acid analogues had been identified to be a novel scaffold of anti-HCV agents with a specific mechanism, and the representative compound 1 demonstrated a moderate anti-HCV activity. The intensive structure–activity relationship of this kind of compounds is explored so as to obtain anti-HCV candidates with good druglike nature. Results Taking compound...

Synthesis, molecular docking and biological evaluation of bis-pyrimidine Schiff base derivatives

Background Heterocyclic pyrimidine nucleus, which is an essential base component of the genetic material of deoxyribonucleic acid, demonstrated various biological activities. A series of bis-pyrimidine Schiff bases were synthesized and screened for its antimicrobial and anticancer potentials. The molecular docking study was carried to find the interaction between active molecules...

Novel pyridine-based Pd(II)-complex for efficient Suzuki coupling of aryl halides under microwaves irradiation in water

Suzuki C–C cross-coupling of aryl halides with aryl boronic acids using new phosphene-free palladium complexes as precatalysts was investigated. A pyridine-based Pd(II)-complex was used in open air under thermal as well as microwave irradiation conditions using water as an eco-friendly green solvent.

Reversible uptake of molecular oxygen by heteroligand Co(II)–l-α-amino acid–imidazole systems: equilibrium models at full mass balance

Background The paper examines Co(II)–amino acid–imidazole systems (where amino acid = l-α-amino acid: alanine, asparagine, histidine) which, when in aqueous solutions, activate and reversibly take up dioxygen, while maintaining the structural scheme of the heme group (imidazole as axial ligand and O2 uptake at the sixth, trans position) thus imitating natural respiratory pigments...

Phenolic compounds, flavonoids, lipids and antioxidant potential of apricot (Prunus armeniaca L.) pomace fermented by two filamentous fungal strains in solid state system

Background The use of agricultural and food by-products is an economical solution to industrial biotechnology. The apricot press residues are abounding by-products from juice industry which can be used as substrates in solid state fermentation process (SSF), thus allowing a liberation and increase of content from various biomolecules with high added value. Methods The evolutions...

Characterization and quantification of flavonoids and saponins in adzuki bean (Vigna angularis L.) by HPLC–DAD–ESI–MSn analysis

Background Bioactive activities of adzuki bean have been widely reported, however, the phytochemical information of adzuki bean is incomplete. The aim of this study was to characterize and quantify flavonoids and saponins in adzuki bean. High performance liquid chromatography with diode array detection and electro spray ionization-tandem multi-stage mass spectrometry (HPLC–DAD...

Formation of amides: one-pot condensation of carboxylic acids and amines mediated by TiCl4

A general procedure for the synthesis of amides via the direct condensation of carboxylic acids and amines in the presence of TiCl4 is reported. The amidation reaction was performed in pyridine at 85 °C with a wide range of substrates providing the corresponding amide products in moderate to excellent yields and high purity. The reaction proceeds with low yields when both the...

The development of an effective synthetic route of lesinurad (RDEA594)

Background Lesinurad is a novel selective uric acid salt transport protein 1 (URAT1) inhibitor which is approved in the USA for the treatment of gout. However, there are some shortcomings among the reported synthetic routes, such as expensive materials, environmental pollution and poor yield. Results In this study, an efficient, practical and environmentally-friendly synthetic...

Synthesis, characterization, anti-ulcer action and molecular docking evaluation of novel benzimidazole-pyrazole hybrids

A series of six novel benzimidazole-pyrazole hybrid molecules was synthesized and characterized using elemental analysis (CHN) and spectroscopic methods (1HNMR, FT-IR). All the synthesized compounds were evaluated for their in vivo anti ulcerogenic activity using Albino rats (weighing 180–220 g). The interactions between the compounds and active site residues of H+/K+ ATPase were...

Two phenolic antioxidants in Suoyang enhance viability of •OH-damaged mesenchymal stem cells: comparison and mechanistic chemistry

Background Suoyang originates from a psammophyte named Cynomorium songaricum Rupr and has been known as a phenolic-antioxidant-enriched traditional Chinese herbal medicine. The present study attempted to investigate the protective effect of phenolic antioxidants in Suoyang towards •OH-mediated MSCs and then further discusses the chemical mechanisms.MethodsThe lyophilized aqueous...

Evaluation of antioxidant profile of various solvent extracts of Carissa opaca leaves: an edible plant

Background Carissa opaca leaves were conventionally recommended by local hakims in Pakistan for curing various human diseases including renal, hepatic and jaundice. In this work we arranged to study the antioxidant status of various fractions of C. opaca leaves through nine multifaceted assay systems. Methods Various fractions were prepared through solvent–solvent extraction...

Comprehensive spectral identification of key intermediates to the final product of the chiral pool synthesis of radezolid

Radezolid (RAD, 12), biaryl oxazolidinone, was synthesised with small modifications according to the methods described in the literature. The pharmacological activity is observed only for (S)-enantiomer, therefore its synthesis is oriented towards obtaining a single isomer of required purity and desired optical configuration. The intermediate products of RAD synthesis were...

Surface bound radicals, char yield and particulate size from the burning of tobacco cigarette

Background Tobacco smoke is a toxic gas-phase cocktail consisting of a broad range of organics, and free radical intermediates. The formation of smoke from a burning cigarette depends on a series of mechanisms, including generation of products by pyrolysis and combustion, aerosol formation, and physical mass transfer processes. Methods The current study simulates the deposition...

One-step multicomponent synthesis of chiral oxazolinyl-zinc complexes

Background Typically, oxazolinyl metal complexes are synthesized in two steps, where the free ligand is prepared by the condensation reaction between a functionalized nitrile and an amino alcohol in the presence of a Lewis or Brønsted acid catalyst, followed by a further reaction with metal salts to obtain the corresponding metal complexes. Very often, the yield afforded by the...

Bis-pyrimidine acetamides: design, synthesis and biological evaluation

BackgroundIn the past few years, increased resistance of microorganisms towards antimicrobial agents become a serious health problem, so there is a need for the discovery of new antimicrobial agents. On the other hand, bis-pyrimidines possess various types of biological activity. In view of this, in the present study we have designed and synthesized a new series of bis-pyrimidine...